The invention relates to a support and guide device for small machine tools, in particular for rotating-mass balancing machines, of the type comprising a base element, at least one moving element in engagement with the base element, support means for the moving element, and drive members controlling shifting of the moving element.
It is known that all machine tools are provided, in addition to a work or cutting motion, with an advance or feed motion causing relative shiftings between the tool and the workpiece.
These relative shiftings take place following a great variety of modalities and among other things involve use of different mechanical members for support and guide. For instance, generally used are slides that, as known, are supports provided with guides and movable along predetermined directions.
Depending on the situations, slides can movably support the workpiece or the tool and each slide is provided for carrying out shifting in a given direction. Slides are important and expensive components in machine tools because accuracy in workings also relies on stability and movement precision of same and because often very precise workings are required.
For instance, in milling machines used as balancing machines for rotating masses, accuracy in the relative shiftings between tool and workpiece must be rather high: in the order of one hundredth of a millimeter.
Balancing machines intervene in some rotors, such as armatures of small electric motors used in cars, household electrical appliances, electrical tooling, to remove small amounts of material at each balancing plane.
In order to achieve a final true accuracy of one or two hundredths of one millimeter in these balancing machines, slides therein used are relatively complicated and expensive, even if traditional in themselves.
Typically, in the concerned slides it is provided that at least two guides with at least two or four ball runners, one ballscrew with the related supports and bearings, a servo-motor operating it and limit sensors, should be mounted on a base. The final cost of these controlled-motion slides is high and setting of same is also very demanding and expensive.
The foregoing is valid in spite of the fact that in this specific case the requested relative shiftings between the workpiece to be balanced during working and the milling tool are of minimum amount.
In fact, as already pointed out, material removal is very reduced and the maximum length of a single milling operation to balance a rotor can be quantified in an amount of about fifteen millimeters.
In addition, a maximum milling depth in a balancing machine is in the order of only three millimeters, although in order to cover the wide variety of diameters of the different pieces that may be submitted to working, an overall maximum stroke of about forty millimeters in the approaching direction between milling tool and rotor is to be stated.
In short, the present art teaches how to manufacture support and guide devices for machine tools having a structure that takes into account the amount of the shiftings to be made only as a marginal question and that, if precision shiftings are required, needs complicated and expensive devices.
This hinders diffusion of small precision machine tools, in particular of said balancing machines.
Under this situation the technical task of the present invention is to conceive a support and guide device capable of obviating the mentioned drawbacks. Within the scope of this technical task it is an important aim of the invention to conceive a device particularly adapted for small shiftings in small machine tools and capable of enabling both high accuracy and minimum costs.
Another important aim of the invention is to conceive a device of simple structure, formed of a minimum number of pieces and of reliable operation.
The technical task mentioned and the aims specified are achieved by a support and guide device for small machine tools, in particular for rotating-mass balancing machines, comprising: a base element, at least one moving element in engagement with said base element, support means for said moving element, and drive members for controlling shifting of same, said support means comprising at least one elastically deformable thin sheet oscillatably supporting said moving element.